brianush1 / zua

Zua

Warning

This project is very much in an alpha stage and should not yet be used in production code

A slow, not yet fully functioning implementation of Lua 5.1

Usage

To build Zua, first cd to the cmdline directory under this folder. Then, run dub build -b release. This will build the Zua command-line utility in release mode. Run ./zua --help for usage.

The path to full* Lua 5.1 support

• ✓ coroutine library

• ✓ math library

• ✓ table library

• ❏ io library

• ❏ debug library (maybe diverge from Lua 5.1)

• ❏ Pattern-matching functions in string library

• ❏ Module system (require, module, and package globals)

• ✓ Add userdata type

• ✓ newproxy function

*Deliberate inconsistencies

Zua does make some decisions about where to deliberately diverge from Lua 5.1. Here is a comperehensive list of where this is done:

• There is no such thing as the "main thread." All code, even toplevel code, runs in a coroutine.

• There is no arbitrary compilation at runtime. This means the globals dofile, load, loadfile, and loadstring are not available.

• The string.dump (and consequently ("").dump) methods are not available; what use were they, anyway?

• Errors do not include line numbers (but the stack trace outputted in the event of an error still does)

• The second argument to the error function is ignored.

• Error messages may differ from Lua 5.1, particularly in parsing.

Any inconsistency between Lua 5.1 and Zua that is not listed above should be regarded as a bug and filed as an issue.

Additions

• Full error position is kept track of, with greater than line precision.

• The parser includes error recovery.